To the extent that this is true, it is not because they are women, but because they have uncommon names, at least uncommon among American public figures. If I say "Kamala is unpopular among inner-city communities", you're likely to know who I'm talking about. If I say the same about "Joe" you're much more likely to be confused.
Additionally, people often say "Trump", "Obama", "Biden". Saying "Clinton" is somewhat ambiguous (Hillary or Bill?). "Harris" could work, but it is definitely a more common name than Kamala.
Additionally there are other women in power who do get referred by their full names. People don't talk about "Marjorie", they use "Marjorie Taylor-Green". They don't talk about Ruth (Bader-Ginsburg) or Diane (Feinstein) or Janet (Yellen) or Margaret (Thatcher).
Additionally, people often say "Trump", "Obama", "Biden". Saying "Clinton" is somewhat ambiguous (Hillary or Bill?). "Harris" could work, but it is definitely a more common name than Kamala.
Additionally there are other women in power who do get referred by their full names. People don't talk about "Marjorie", they use "Marjorie Taylor-Green". They don't talk about Ruth (Bader-Ginsburg) or Diane (Feinstein) or Janet (Yellen) or Margaret (Thatcher).